Recent advances in photorelease complexes for therapeutic applications

Photorelease complexes represent a class of agents for which UV-visible light triggers the expulsion of a specfic molecule that is intrinsically part of the inner coordination sphere or held in close proximity to the metal centre. The reaction does not occur in the ground-state complex and requires a photon, but an additional agent may be present that facilitates the release process. In this context, the perspective article covers recent papers from the past five years (2017-2021) on metal-based complexes containing ligands that are expelled under light activation. In addition, the examples primarily focus on ligands with potential biological activity and have specfic therapeutic applications. Some examples include NO, CO, Cl^-, peptides, pharmacophores and redox-active compounds.